Piano-bridge.



PATENTED FEB. 13, 1906.

F. MEYER.

PIANO BRIDGE.

APPLICATION rmm 00m. 6,1904.

UNITED STATES PATENT OFFICE.

Specification of Letters Patent.

Patented Feb. 13, 1906.,

Application filed October 5, 1904. Serial No. 227,330.

To all whom it may concern.-

Be it known that I, FRANZ MEYER, a citizen of the United States,residing at Oak Park, in the county of Cook and State of Illinois, haveinvented certain new and useful Improvements in Piano-Bridges, of whichthe following is a specification.

This invention relates to improvements in pianos, and refers morespecifically to an improved construction in the sounding-board bridges,which support the strings and transmit the vibrations to thesounding-board, and in the string-supports used in conjunctiontherewith.

The salient object of the present invention is to improve the qualityand volume of the tone by the adoption of a peculiar construction andarrangement of the sounding-board and bridges.

Secondary objects of the invention are to provide a construction whichenables practically the entire area of the sounding-board to be utilizedfor vibration and caused to vibrate freely at all times, whether thevibration be imparted thereto through bass or treble strings; to providea construction in which the location of the bridges through which thevibrations of the strings are imparted to the sounding-board is thesame, or practically the same, for both bass and treble strings, wherebyperfect uniformity of tone throughout the full register of the piano ismade feasible; to provide a construction which is alike available forpianos of the various types now commonly in use; to provide aconstruction which by utilizing the full area of the sounding-boardenables the latter to be of somewhat smaller dimensions than hasheretofore been possible; to produce a given volume of sound, and ingeneral to provlde a simple and improved construction and arrangement ofthe character referred to.

To the above ends my invention consists in the matters hereinafterdescribed, and more particularly pointed out in the appended claims.

The invention will be readily understood from the following description,reference being had to the accompanying drawings, in which Figure 1 is atransverse sectional view taken through that side of the sounding-boardwhich supports bridges and showing also in section parts of thesurrounding and supporting frame members. Fig. 2 is a sectional Viewtaken approximately at right angles to that shown in Fig. 1 on the line2 2 and looking in the direction of the arrows. Fig. 3 is a view similarto Fig, 2, showing a slightlymodified construction of the bass bridge.Fig. 4 is a view similar to Fig. 1, but showing a slightly-modifiedconstruction; and Fig. 5 is a view similar to Fig. 2, taken on line 5 5of Fig. 4 and looking in the direction of the arrows,

In stringing pianos it is of course necessary in order to secure aproper distribution of the bass and treble strings over the soundingboard and a proper disposition of both thereon that the bass bridge,which supports the bass strings, be located at some distance outside ofor toward the margin of the soundingboard from the treble-string bridge.It has heretofore been the practice to interpose the bass bridgedirectly between the strings and the sou1iding-board'in its properposition relatively to the length of the bass strings and likewise tointerpose the treble bridge between the treble strings and soundingboardin its proper position with relation to the length of the treblestrings. In this arrangement of course the vibrations of the two sets ofstrings are imparted to the soundingboard at two quite widely-separatedpoints, with the result that the bass bridge acts to some extent as amuflie to interfere with the vibrations of the board when the treblestrings are sounded, and similarly the treble bridge acts as a muflle tointerfere with the vibrations of the sounding board when the bassstrings are sounded. These defects have been recognized heretofore, andit has been proposed to avoid the same by providing independentsounding-boards, one for the set of treble strings and another for theset of bass strings. It has also been customary to make thesounding-boards of relatively large area for the purpose of minimizingthe objec tionable mufliing and interfering vibration ef fects incidentto the usual arrangement of bridges. A marked effect, and perhaps the'one which is most serious, incident to the old construction is that itis impossible to secure a perfectly uniform tone-register, there beinginevitably. a break in the tone in the step between the treble and bassregisters. Various expedients have been adopted to minimize and concealthis break, particularly the use of strings specially constructed tocompensate for the difference in tone effect due to the differentpositions of bridge contact with the sounding-board. In the presentinvention I overcome these defects by supporting both bridges from acommon line on the sounding-board, so that the vibrations imparted tothe sounding-board,whether derived from bass or treble strings, aretransmitted to the board at the same place, and the entire area of thesounding-board inside of its marginal supports is undampered, unmuffied,and vibrates freely.

In the drawings I have shown so much of a piano mechanism as isnecessary to understand a simple embodiment of the invention.

Referring to Figs. 1 and 2, 1 designates a sounding-board, 2 therim-frame, upon which the sounding-board is mounted, and 3 the marginalor casing frame, within which the sounding-board is seated. 4 designatesas a whole a string-supporting frame, which in the present instancetakes the form of a skeleton casting having a marginal portion 5,conforming to the marginal configuration of the sound ing-board andsuitably secured to the latter, as indicated at 6. Said frame member 4is provided with bar members 7, which extend parallel or substantiallyparallel with the strings of the instrument and are spaced apart somedistance, as indicated in Fig. 2, and at a point some distance inside ofthe rim or toward the center of the board a crossbar 8 extends betweenthe bars 7 and forms a support for the ends of the treble strings 9, asindicated clearly in Fig. 1. The bass strings extend above and beyondthe treble strings and are secured to the marginal member 5 of theframe, as shown clearly in the drawings. 10 designates the treblebridge, which is mounted upon the sounding-board in the usual manner,and 11 designates the bass bridge, which is, as usual, located betweenthe treble bridge and the margin of the sounding-board. The bass bridge,however, instead of resting directly upon the soundingboard at its footis carried by a structure which is connected with the sounding-board ata point substantially coincident with the foot of the treble bridge 10.In the construction shown in Figs. 1 and 2 this bassbridge supportingstructure comprises a bracket 12, secured to the under side of thesounding-board, and a series of pins or supports 13, connected with thefree end of the bracket, extending upwardly through suitable apertures14 in the sounding-board and connected with the foot portion of thebridge. The foot portion 15 of the bracket is rigidly connected with thesounding-board at a point as nearly coincident with the foot of thetreble bridge as may be and still permit the insertion of thesecuring-screws 16 through the sounding-board and into the foot of thebracket and bridge, respectively. The

bracket 12 and supporting-pins 13, carried thereby, are free fromcontact with the sounding-board except as the foot of the bracket isunited to the board, the apertures 14 being larger than the ins 13, asindicated clearly in the figures of the drawings. It follows that thevibrations from the strings are imparted to the sounding-boardat'substantially the same point or transverse line both through the bassand treble bridges, and since the ends of the two sets of strings aresupported by the frame member 4 free from the sounding-board the latteris unmuffied and free to vibrate throughout its entire area.

In Fig. 3 the construction is substantially identical with that shown inFig. 2, except that in lieu of the series of pins 13 a single bridgemember 13 is extended down to and connected with the supporting-bracket.

In Figs. 4 and 5 I have shown a modification which is theoretically moreperfect than that shown in Figs. 1, 2, and 3. In this modification thefoot 15 of the bracket 12 is arranged in exact register with the opposedfoot of the treble bridge 10, and the securingscrews 16 are insertedthrough the bracket, the interposed portion of the sounding-board, andinto the bass portion of the treble-bridge. In this instance also thebass bridge 11 is provided with extensions 17 forming feet which extendthrough suitable openings 14 in the sounding-board and are directlyconnected with the main body of the bracket. By thus connecting the bassbridge to the under side of the sounding-board I transmit the stress ofthe strings in a better manner than would be the case were both bridgessupported from the same point upon one side of the sounding-board only.The principle of transmitting the vibrations from both treble and bassstrings to the same part of the sounding-board would, however, remainthe same if the construction last suggested be adopted.

It will be obvious from the foregoing description that the details ofconstruction may be modified without in any sense departing from thespirit of the invention, and I do not, therefore, limit myself todetails of construction and arrangement except to the extent that theyare made the subject of specific claims.

I claim as my invention 1. In a piano, the combination with the soundingboard of two string supporting bridges spaced apart as to theirstring-engaged edges but connected to the soundingboard at the samecommon location, or suostantially so.

2. In a piano, the combination with the sounding-board and sets of bassand treble strings, of a bass-string bridge and a treblestring bridge,both of said bridges having vibration imparting engagement with thesounding-board at substantially the same place.

3. In a piano, the combination with the sounding-board andsupporting-frame therefor, of a treble bridge applied to one side ofsaid sounding-board at a point removed from the margin of the board, abass bridge arranged between the treble bridge and margin of the board,and supporting de ices connected with said bass bridge extending throughopenings in the sounding-board and connected with the opposite side ofthe latter at a location substantially coincident with the location ofengagement therewith of the treble bridge.

4. In a piano, the combination with the sounding-board andsupporting-frame therefor, of a bridge applied to one side of saidsounding-board and supporting one set of strings, a second bridgearranged to support a second set of strings at a location removed fromsaid first bridge, and supporting devices connected with said secondbridge extending through the sounding-board and arranged in vibrationtransmitting engagement with the opposite side of the soundingboard at alocation substantially coincident with the engagement therewith of thefirstnamed bridge.

5. In a piano, the combination of a sounding-board, a marginal framesupporting said board, a string-supporting frame connected with saidmarginal frame, a set of treble strings connected with a part of thestringsupporting frame which overhangs the sounding-board, a set of bassstrings connected with the marginal portion of said stringsupportingframe, a treble bridge interposed between the treble strings andsoundingboard and having direct bearing with the latter, a bass bridgesupporting the bass strings, and a bracket supporting said bass bridgeand having its foot portion connected with the soundingboardsubstantially in register with the line of engagement of the treblebridge.

6. In a piano, the combination of a sounding-board, a marginal framesupporting said board, a string-supporting frame connected with saidmarginal frame, a set of treble strings connected with a part of thestringsupporting frame which overhangs the sounding-board, a set of bassstrings connected with the marginal portion of said stringsupportingframe, a treble bridge interposed between the treble strings andsoundingboard and having direct bearing with the latter, a bass bridgesupporting the bass strings, and a bracket supporting said bass bridgeand having its foot portion connected with the sounding-boardsubstantially in register with the line of engagement of the treblebridge but at the opposite side of the board, substantially asdescribed.

7. In a piano, the combination with a sounding-board andsupporting-frame therefor, of a treble bridge applied to one side ofsaid sounding-board at a location removed from the margin of the board,a bass bridge arranged between the treble bridge and proximate margin ofthe board and a supporting-frame connected with said bass bridgeextending freely through the sounding-board and connected to the underside of the latter at a location removed from and inside of the bassbridge.

FRANZ MEYER.

Witnesses:

ALBERT W. GRAVES, WILLIAM OonBETT.

